Scientists have documented five major mass extinction events in Earth's history, during which at least three-quarters of life went extinct. But with humans clearing habitats, exterminating species and ...

Farther back in our planet’s history, volcanic eruptions, rapid climate change, and plummeting oxygen levels have caused at least four additional mass extinctions, with smaller pulses of biodiversity ...

Humans have been shaping their environment since time immemorial. From cities to farms to highways, our impact has grown so large that we've pushed planetary boundaries, fueling concerns about climate ...

CREDIT: Nick Fitzhardinge via Getty Images. Get the Popular Science daily newsletter💡 Breakthroughs, discoveries, and DIY tips sent every weekday. Terms of Service ...